/*-
* Copyright (c) 1999 The NetBSD Foundation, Inc.
* All rights reserved.
*
* Copyright (c) 1999, 2003 Marcel Moolenaar
*
* This code is derived from software contributed to The NetBSD Foundation
* by Klaus Klein.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
/* XXX fix this, just get to compile for now */
#define _NGREG 1
#ifndef __ASSEMBLER__
typedef unsigned long __greg_t;
typedef __greg_t __gregset_t[_NGREG];
typedef struct {
union _ia64_fpreg __fpregs[_NGREG];
} __fpregset_t;
#endif /* __ASSEMBLER__ */
/*
* The mc_flags field provides the necessary clues when dealing with the gory
* details of ia64 specific contexts. A comprehensive explanation is added for
* everybody's sanity, including the author's.
*
* The first and foremost variation in the context is synchronous contexts
* (= synctx) versus asynchronous contexts (= asynctx). A synctx is created
* synchronously WRT program execution and has the advantage that none of the
* scratch registers have to be saved. They are assumed to be clobbered by the
* call to the function that creates the context. An asynctx needs to have the
* scratch registers preserved because it can describe any point in a thread's
* (or process') execution.
* The second variation is for synchronous contexts. When the kernel creates
* a synchronous context if needs to preserve the scratch registers, because
* the syscall argument and return values are stored there in the trapframe
* and they need to be preserved in order to restart a syscall or return the
* proper return values. Also, the IIP and CFM fields need to be preserved
* as they point to the syscall stub, which the kernel saves as a favor to
* userland (it keeps the stubs small and simple).
*
* Below a description of the flags and their meaning:
*
* _MC_FLAGS_ASYNC_CONTEXT
* If set, indicates that mc_scratch and mc_scratch_fp are both
* valid. IFF not set, _MC_FLAGS_SYSCALL_CONTEXT indicates if the
* synchronous context is one corresponding to a syscall or not.
* Only the kernel is expected to create such a context and it's
* probably wise to let the kernel restore it.
* _MC_FLAGS_HIGHFP_VALID
* If set, indicates that the high FP registers (f32-f127) are
* valid. This flag is very likely not going to be set for any
* sensible synctx, but is not explicitly disallowed. Any synctx
* that has this flag may or may not have the high FP registers
* restored. In short: don't do it.
* _MC_FLAGS_SYSCALL_CONTEXT
* If set (hence _MC_FLAGS_ASYNC_CONTEXT is not set) indicates
* that the scratch registers contain syscall arguments and
* return values and that additionally IIP and CFM are valid.
* Only the kernel is expected to create such a context. It's
* probably wise to let the kernel restore it.
*/
